New Therapy Will Prevent Growth of Bone Formations That Hamper Amputees' Use of Prostheses

CMU's Jeffrey O. Hollinger, director of the center, and Professor Krzysztof Matyjaszewski have received a three-year, $2.9 million U.S. Department of Defense research grant to develop a therapy that would aid amputees, specifically wounded soldiers. The therapy aims to prevent bone nodules from forming in the muscle at the site of amputation, a painful condition that makes it difficult for amputees to wear limb prostheses.

"This grant will help us prevent heterotopic ossification at the amputation stumps in military troops wounded in combat. Our work is critical as amputations increase with the current surge in Afghanistan," Hollinger said.

Amputations among wounded soldiers increased more than 60 percent, from 47 in 2009 to 77 through Sept. 23 of this year, according to U.S. Army reports. The chief causes of amputations are injuries from improvised explosive devices, or IEDs, that are planted in the ground or along roads.

When a limb is amputated, whether by surgical means or as the result of a violent injury, bone can begin to form in the body's soft tissue through a process called heterotopic ossification. Through the new grant, Hollinger and Matyjaszewski, the J.C. Warner Professor of Natural Sciences at CMU's Mellon College of Science, will develop new tools that will help prevent the growth of these painful bone formations in the muscles of amputees. The bone formations can make it difficult for amputees to wear limb prostheses.

"We are developing novel nano-structured polymers that will place selective biological cues at the stump site to block the bone formation cascade in the soldier's traumatized muscle," said Hollinger, who also is director of the Craniofacial Program, one of five programs funded under the Rutgers-led consortium in the Armed Forces Institute of Regenerative Medicine. Hollinger's program is researching therapies to help heal combat injuries to the face and jaw.

Matyjaszewski, renowned for developing a method that allows for nanoscale control over the polymers formation, said the ability to control and block mineralization and bone formation opens up many compelling opportunities for increased research. Heterotopic ossification can occur in a number of situations other than amputation, most commonly after joint replacement surgery.

The new research grant also will support two research staffers, three full-time Ph.D. students and one post-doctoral fellow.